Alloy C276

Titanium

Nickel

Overview

Grades & Materials

Pure Nickel

Nickel–Chromium Alloys

Nickel–Molybdenum Alloys

Nickel–Chromium–Molybdenum Alloys

Alloy 625

Alloy C276

Alloy C22

Nickel–Iron Alloys

Applications

Products

Standards & Quality

Technical Knowledge

Selection Guide

Stainless

Carbon

Alloy

Copper, Brass and Bronze

Alloy C276

Alloy C276 is a nickel–chromium–molybdenum (Ni–Cr–Mo) alloy developed for maximum corrosion resistance in extremely aggressive and unpredictable environments.
It is especially valued for its ability to withstand mixed acids, chlorides, and fluctuating oxidizing/reducing conditions, making it a go-to material for high-risk chemical processing and critical heat exchanger service.

Within the Ni–Cr–Mo family, Alloy C276 is positioned as a corrosion-first grade, often selected when process upsets or variable chemistry are expected.

Chemical & Metallurgical Characteristics

Alloy C276 uses a carefully balanced Ni–Cr–Mo chemistry to suppress multiple corrosion mechanisms simultaneously.

Key Metallurgical Features

  • High nickel content for matrix stability

  • Chromium for oxidation resistance and SCC mitigation

  • Molybdenum for resistance to pitting and crevice corrosion

  • Low iron content to improve corrosion reliability

  • Stable FCC microstructure with excellent ductility

This balance allows Alloy C276 to tolerate process variability better than many corrosion-resistant alloys.

Corrosion Resistance Performance

Alloy C276 is designed for broad and severe corrosion exposure.

Excellent Resistance In:

  • Mixed oxidizing and reducing acids

  • Chloride-containing environments

  • Pitting and crevice corrosion

  • Stress corrosion cracking

  • Wet chlorine, hypochlorites, and ferric solutions

Limitations:

  • Higher cost compared with Alloy 625

  • Mechanical strength is secondary to corrosion performance

  • May be over-specified for stable, well-controlled processes

Alloy C276 is frequently chosen when corrosion risk outweighs all other considerations.

Mechanical Properties (Typical)

Alloy C276 provides:

  • Moderate tensile and yield strength

  • Excellent ductility and toughness

  • Stable mechanical behavior across a wide temperature range

While not the strongest Ni–Cr–Mo alloy, it delivers exceptional reliability in corrosive service.

Typical Applications

Alloy C276 is widely used in the most corrosion-critical equipment.

Common Applications Include:

  • Chemical reactors and vessels

  • Heat exchangers in mixed-acid service

  • Flue gas desulfurization (FGD) systems

  • Acid recovery and regeneration units

  • Pulp & paper chemical processing equipment

In many EPC projects, Alloy C276 is specified when material failure is not an option.

Product Forms Available

Alloy C276 is commonly supplied as:

  • Seamless tubes

  • Pipes

  • Plates and sheets

  • Bars and rods

  • Forgings, fittings, and tube sheets

For chemical and thermal equipment, seamless Alloy C276 tubes are preferred for:

  • Uniform wall thickness

  • Reliable pressure integrity

  • Consistent corrosion resistance

Manufacturing & Fabrication

Alloy C276 is suitable for fabrication with proper controls:

  • Hot and cold working

  • Solution annealing

  • Conventional welding with clean procedures

Good fabrication practice is essential to maintain corrosion resistance and weld integrity.

Standards & Specifications

Alloy C276 products are typically supplied to:

  • ASTM material standards

  • ASME pressure equipment codes

  • Project-specific chemical service specifications

Typical Inspection & Testing:

  • Chemical composition analysis

  • Mechanical testing

  • Dimensional inspection

  • Eddy current or ultrasonic testing (for tubes)

  • PMI verification

Full Mill Test Certificates (MTC) and traceability are standard.

Alloy C276 vs Alloy 625 (Concept)

  • Alloy C276

    • Maximum corrosion resistance

    • Excellent tolerance to process upsets

    • Preferred for severe chemical environments

  • Alloy 625

    • Better balance of strength and corrosion resistance

    • Superior for pressure-bearing and structural service

    • More cost-effective for general mixed environments

Selection depends on whether corrosion severity or mechanical strength is the dominant requirement.

Summary

Alloy C276 is positioned within Nickel → Grades & Materials → Nickel–Chromium–Molybdenum Alloys and is selected for extreme and variable corrosive environments.

Explore next:

  • Grades: Alloy 625 · Alloy C22

  • Applications: Heat Exchangers · Chemical Processing · Marine & Offshore

  • Guide: Nickel Selection Guide